No abstract

The reverse analysis method is presented to determine the flow stress of magnesium alloy sheet AZ31B based on limiting dome height tests. The determination of flow stress is treated as an optimization problem by the reverse analysis technique. The unknown coefficients in the flow stress equation are regarded as design variables, and the difference between experimental loads and corresponding predictions by the finite-element method is calculated as an objective function. The response surface method is used to solve this optimization problem, and the flow stress of the material is determined by optimal values of design variables. In this study, the flow stress of an AZ31B sheet is determined at 250°C by reverse analysis. The limiting dome height tests for AZ31B sheet are carried out and sampling points are chosen from load against stroke curve. The finite-element analysis model for the sheet forming according to the test condition is set up. The numerical simulations are performed with sample values of design variables and objective functions are calculated. The response surface equation is formulated by the regression analysis and the optimal values of design variables are obtained by minimizing the equation.

Private Offered Fund develops very rapidly in China, it has become a very important part of financial market. It has important insignificant that study the risk system to steady the financial market of China. In this research, we established system of risk assessment of private offered fund in China and assessed the risk level of each indexes by using AHP-Fuzzy Comprehensive Evaluation Methods. The result shows that credit risks, business risks and liquidity risks are the most important factors of private offered fund system. The holistic risk of private offered fund in China stands at a high level at present, in which credit risks and liquidity risks are the highest ones.

Information technology has become a consensus today, at the same time, we need to integrate and deal with the huge data. Especially in some specific areas, such as rapid reaction system, the whole reaction process is less than 5s. To analyze the entire reaction process to understand the parameters of the change, even with the 500ms sampling cycle, the data collection is still too little. In this case, resource consumption on the machine for communication with the controller system has been very high, coupled with data processing, images, database tasks and etc. When the scale of variable size is not much, the host computer load has been overwhelmed. The use of acquisition board to achieve high-speed data acquisition is limited by the size of the entire system limitations, and also because of the number of computer expansion slot restrictions, the final number of points are dozens. Based on the above problems we combine s7-300PLC with WinCC for high-speed collection of information to achieve the value of large data extraction.